A variety of tensioning systems for mobil machines driven on endless tracks have been used in the past. These systems provide tension on the endless track for motive effort. In the past some arrangements have included a lead screw and adjusting nut to advance an idler wheel away from a drive wheel in order to tension the endless track. However, this arrangement does not allow recoil or deviation of the chain or idler wheel during operation. Other arrangements have included additional components such as springs, grease filled systems, and complicated mechanical assemblies to provide tension and permit recoil.
Hydraulic systems are typically utilized today to provide tension and recoil functions on endless track laying machines. Systems are designed so that a range of operating conditions can be withstood. Components are sized to handle normal operating conditions as well as higher stresses to allow recoil and extreme tension requirements adding additional weight and cost. Some systems are complicated and use various monitoring apparatus, such as pressure sensors to measure hydraulic system pressure, or position sensors to sense the position of the idler wheel or tensioning cylinder. When a recoil event or high-pressure spike is sensed, fluid is bled off to a reservoir, lowering the pressure in the system, and then is reintroduced by a fluid supply pump when the pressure returns to a normal state.
The prior art tension and recoil systems described above require continuous attachment to a pressurized fluid supply source, use excessively robust components or sophisticated monitoring systems.
The present invention is directed to overcome one or more of the problems as set forth above.